Intrinsic Semiconductor
Intrinsic Semiconductor - Related Videos
12:36
Semiconductors
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2023
Source: Derek Wilson, Asantha Cooray, PhD, Department of Physics & Astronomy, School of Physical Sciences, University of California, Irvine, CA Semiconductors are materials whose ability to conduct an electrical current depends strongly on their temperature and level of impurity. The most common type of semiconductor material is crystalline silicon. Most pure semiconductors are not outstanding conductors; to improve conductivity, a pure semiconductor is often combined or "doped" with an...
01:22
Semiconductors
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2024
There is variation in the electrical conductivity of materials - metals, semiconductors, and insulators that are showcased with the help of the energy band diagrams. Metals such as copper (Cu), zinc (Zn), or lead (Pb) have low resistivity and feature conduction bands that are either not fully occupied or overlap with the valence band, making a bandgap non-existent. This allows electrons in the highest energy levels of the valence band to easily transition to the conduction band upon gaining...
11:14
Comprehensive Characterization of Extended Defects in Semiconductor Materials by a Scanning Electron Microscope
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Cited by 4 •
2016
The optical, electrical, and structural properties of dislocations and of grain boundaries in semiconductor materials can be determined by experiments performed in a scanning electron microscope. Electron microscopy has been used to investigate cathodoluminescence, electron beam induced current, and diffraction of backscattered electrons.
02:18
Intrinsically Disordered Proteins
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2020
Intrinsically disordered proteins are a group of proteins that do not fold into specific three-dimensional structures. Their structural flexibility allows them to complement ordered proteins to perform functions that are inaccessible to rigid structures. They are more common in eukaryotes than prokaryotes and may either be exclusively intrinsically disordered or hybrid proteins, consisting of a mix of ordered and disordered regions. The absence of a rigid structure in these proteins can be...
01:24
Metal-Semiconductor Junctions
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2024
The contact of metal and semiconductor can lead to the formation of a junction with either Schottky or Ohmic behavior. Schottky Barriers Schottky barriers arise when a metal with a work function (Φm) contacts a semiconductor with a different work function (Φs). Initially, electrons transfer until the Fermi levels of the metal and semiconductor align at equilibrium. For instance, if Φm > Φs, the semiconductor Fermi level is higher than the metal's before contact. The semiconductor's...
FAQs
The band gap sets the energy difference that electrons must cross to move from the valence band into the conduction band. Thermal energy can supply this transition, producing an electron in the conduction band and a corresponding hole in the valence band. Consequently, the material’s carrier population and conductivity depend strongly on temperature relative to its band gap.
Each thermally generated conduction-band electron leaves behind one hole in the valence band. Because these carriers arise as paired excitations within the same material, their concentrations remain equal under thermal equilibrium. This balanced carrier population distinguishes the intrinsic state from intentionally doped conditions, where one carrier type becomes more prominent.
Conductivity depends on both how many mobile carriers are available and how readily those carriers move through the material. Thermal excitation increases the number of electrons and holes, while mobility describes their movement within the semiconductor. Engineering analyses therefore consider both quantities rather than treating carrier concentration alone as a complete measure of electrical behavior.
An intrinsic semiconductor represents the material’s undoped reference condition, with carrier behavior determined by its own atomic structure and thermal excitation. Doping intentionally changes that carrier behavior. Comparing the two states helps engineers identify the effects of added impurities and understand how carrier concentrations influence later structures such as p-n junctions and transistor materials.
The intrinsic state provides a baseline for understanding what changes when semiconductor regions receive intentional impurity doping. Engineers can compare the equal thermally generated electron and hole populations of the pure material with the altered carrier behavior in doped regions. This comparison supports analysis of p-n junctions, transistors, and the electrical differences created by material engineering.
Temperature changes the thermal energy available for promoting electrons across the band gap. As temperature increases, more electron-hole pairs can form, generally increasing conductivity. This behavior matters when engineers evaluate device performance because temperature can alter the semiconductor’s carrier population and therefore contribute to thermal effects in components and systems.
Intrinsic carrier behavior supplies a reference for interpreting temperature-dependent electrical changes in semiconductor sensors. Because thermal excitation affects electron-hole pair generation and conductivity, engineers can relate changes in electrical behavior to temperature conditions. The same reference also helps distinguish material-intrinsic effects from changes introduced through intentional doping or device design.